If you're doing a rebase or merge or any other operation, and a conflict comes up, in git you have to resolve it right now, or discard everything. You can't just leave the conflicts in place while you work on something else, they effectively freeze your entire repo. JJ is the opposite. You'll get conflicts, it will tell you about them, but it's up to you to choose when to work on them. You can even keep piling new changes on top of a conflicted one. Your program probably won't work, being full of conflict markers, but you can keep working still
You can also resolve the conflict markers in a variety of different styles, not just edit in place.
Say I'm doing a dependency update, and someone else updated different dependencies, and our change sets merge. I want both sets of updated versions, but our lockfiles probably conflict, and I don't want to edit them by hand. I can just leave the conflicted lockfiles till the end of the rebase/merge, then purge them and regenerate them using tooling, and then split them up and apply them down to their respective conflicting changes.
Sure beats having to toss the lockfile, regen it, then let the rebase continue only to find you have to do it AGAIN
